Process for the manufacture of detonating compositions for detonators or primers



' ing the Patented June 17,1924.

UNITED STATES.

PATENT OFFICE.

EDMUND VON HERZ, F CHARLOTTENBURG, GERMANY.

PROCESS FOR THE MANUFACTURE or DETONATING COMPOSITIONS FOR- DETONATORS on. PRIMERS.

No Drawing. Application filed July 5,

To all whom it may concern:

Be it known that I, EDMUND VON HERZ,

a citizen of the Republic of Austria, residing in Charlottenburg, Germany, have invented certain new and useful Improvements in Processes for the Manufacture of Detonating Compositions for Detonators or Primers, of which the following is a specification.

Recently the fulminate of mercury hitherto used in detonators or primers has been successfully replaced by heavy metal salts of hydrazoic acid or azoimide. The most important of these salts, which is the one 1 that is almost exclusively used, is that of lead, the lead azide.

This otherwise effective detonator has however some drawbacks which for .a considerable time stood in the way of its extensive technical use. These are the sensitiveness to damp or to air containing carbonic acid, the relatively diflicult ignition and the insufficient strength of the pressed mass.

To avoid the said drawbacks it has been attempted either to mix lead azide with 7 other suit-able explosive substances or to impress on the lead azide, a layer of the said substances, for the purpose of increascompressibility and the power of ignition, and by enclosing the lead azide of rendering the action of carbonic acid -im-' possible. No satisfactory result was obtained with the explosive substances first suggested, such as fulminate of mercury, black and nitrocellulose powders, potassium picrate, mixtures of potassium chlorate and perchlorate with lactose and lead rhodanate, trinitrotoluol, tetranitromethylanilin, asbes- 9 tos powder etc, as either the object was not attained, or other serious drawbacks were produced.

Complete success was obtained only by the use of the lead salt 'of styphnic acid, the normal lead trinitroresorcinate. This salt can be packed as a separate layer, or also mixed .direct with lead azide. The latter method is to be preferred on account of greater economy in material, as when charging or packing of the mixture, the total quantity of the two explosives can be smaller than when the two layers are packed or charaged separately. On the other hand, the mixing of two such highly explosive substances requires a 1922. Serial No. 572,962.

special installation with protective devices, and finally it has been observedthat during treatment of the mixtures, unlike in the case of packing or charging separately, press explosions are liable to take place.

According to the present invention a process for the manufacture ofdetonating compositions for military, mining and like purposescontaining heavy metal azides in association with other salts, is characterized by simultaneous production of the salts in admix ure in a non-solvent liquid. joint product is separated from the liquid as may be desired, preferably by precipitation.

In that way not only is a whole operation economized, but the mixing can be carried out perfectly safely, and with a thoroughness which cannot be attained by ordinary mixing processes. This is due to the fact that in this new method it is a question not of mixing, but of single crystals of the two salts settling on each other. The separating crystals become attached to each other in such a manner that finally a homogeneous mass is produced which moreover shows the highly important advantage that the constituents cannot be separated. The vibrations of the packing or charging device do not produce, like in the case of ordinary mixing, separation and gradual stratification in accordance with the specific gravities, and the proportions of the mixture remain constant under all circumstances. The mixture produced in the way described is also much less sensitive to mechanical influences than a simple mixture: press explosions can scarcely take place. This is probably the consequence of the ar rangement of the single crystals, due to the process of crystallization.

The two salts can be precipitated together from a joint solution, or the precipitation may be carried out in the presence of oneof the salts already produced and suspended in'the solution containing the other.

The first method is carried out by causing a solution of sodium azide and magnesium trinitroresorcinate to flow slowly into lead nitrate solution at a temperature of at least degrees (1., slightly acidified with acetic acid. This method of preparation is inferior to the second one to be described, as the higher temperature required for precipitation, is liable to favour the formation The of larger lead azide crystals owing to which the detonating composition is liable to become dangerous when carelessly handled.

The second method, consists in suspending lead trinitro-resorcinate obtained by the well known process, in an aqueous lead acetate solution and in allowing a diluted solution of sodium azide to flow in very' slowly at the ordinary temperature. The

proportions are preferably calculated so What' I claim as my invention and desire to secure by Letter Patent is 2.-

1'. In the manufacture of detonating compositions producing a heavy metaLazide in initial homogeneous admixture with lead trinitro-resorcinate by a process of precipitation wherein an easily soluble azide and a heavy metal salt that will react with the azide to produce a heavy metal azide, are caused by an admixture of their solutions to react and produce in the presence of lead trinitro-resorcinate so as to be homogeneously admixed -in the liquid therewith the heavy metal azide in the form of a precipitate, and by afterwards separating the admixed compounds from the liquid.

2. In a process for the productlon of detonating compositions, the'steps which consist in taking an azide and a heavy metal salt which will react with the azide to. produce a heavy metal azide, causing the two salts to react. together in solution in the presence of lead trinitro-resorcinate so as of the heavy metal azide'and lead trinitro- .resorcinate, and thereafter separating the suspended salts from the liqui 3. In a process for the production of detonating compositions, the steps which consist in taking an azide and a lead salt which will react with the azide to pro duce lead azide, causing the two salts to react together in solution in the presence of lead trinitro-resorcinate so as to produce a homogeneous mixture in liquid of lead azide and lead trinitroresorcinat, and separating the suspended salts fromthe liquid.

4. A process for the production of detonating compositions wherein lead trinitroresorcinate is suspended in a solution of a heavy metal salt and a solution of an azide capable of reacting with said salt and producing a heavy metal azide is introduced into the first mentioned solution to produce a separation out from solution of the heavy metal azidein the presence of the suspended lead trinitro -resorcinate.

onating compositions whereinf lead trinitroresorcinate is suspended in an aqueous solution of lead acetate and a solution of sodium azide is introduced.

6. A; process for the production of detonating compositions wherein lead trinitroresorcinate is suspended in an aqueous solution of lead acetate and a dilute solution of sodium azide is gradually introduced.

7.. A process for the production of detonating compositions. wherein lead trinitroresorcinate is suspended inan aqueous solution of lead acetate and a dilute solution of sodium azide is gradually introduced in such proportion that a mixed precipitate is obtained containing from forty to fifty per cent of lead azide.

In testimony whereof I aflix my signature.

EDMUND VON HERZ.

5. A process for the production of deta 

